/*
* Copyright (c) 2004-2005, Swedish Institute of Computer Science.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of the protothreads library.
*
* Authors: Adam Dunkels <adam@sics.se>, Sandro Magi <naasking@gmail.com>
*
* $Id: example-buffer.c,v 1.5 2005/10/07 05:21:33 adam Exp $
*/

#ifdef _WIN32
#include <windows.h>
#else
#include <unistd.h>
#endif
#include <stdio.h>

#include "async.hpp"

#define NUM_ITEMS 32
#define BUFSIZE 8

static int buffer[BUFSIZE];
static int bufptr;

static void
add_to_buffer(int item)
{
  printf("Item %d added to buffer at place %d\n", item, bufptr);
  buffer[bufptr] = item;
  bufptr = (bufptr + 1) % BUFSIZE;
}
static int
get_from_buffer(void)
{
  int item;
  item = buffer[bufptr];
  printf("Item %d retrieved from buffer at place %d\n",
    item, bufptr);
  bufptr = (bufptr + 1) % BUFSIZE;
  return item;
}

static int
produce_item(void)
{
  static int item = 0;
  printf("Item %d produced\n", item);
  return item++;
}

static void
consume_item(int item)
{
  printf("Item %d consumed\n", item);
}

static async::semaphore full, empty;

TASK(producer)
{
  int produced;

  TASK_BEGIN

    for (produced = 0; produced < NUM_ITEMS; ++produced) {

      AWAIT(full);

      add_to_buffer(produce_item());

      empty.signal();
    }

  TASK_END
};

TASK(consumer)
{
  int consumed;

  TASK_BEGIN

    for (consumed = 0; consumed < NUM_ITEMS; ++consumed) {

      AWAIT(empty);

      consume_item(get_from_buffer());

      full.signal();
    }

  TASK_END
};


TASK(driver_thread)
{
  producer prod;
  consumer cons;

  TASK_BEGIN

    empty.reset(0);
    full.reset(BUFSIZE);

    AWAIT(prod() & cons());

  TASK_END;
};

int example_buffer(void)
{
  //struct async driver_pt;

  //async_init(&driver_pt);

  driver_thread driver_thread;

  while (!driver_thread()) {

    /*
    * When running this example on a multitasking system, we must
    * give other processes a chance to run too and therefore we call
    * usleep() resp. Sleep() here. On a dedicated embedded system,
    * we usually do not need to do this.
    */
#ifdef _WIN32
    Sleep(0);
#else
    usleep(10);
#endif
  }
  return 0;
}
